2.3. Baking performance test
2.4. Uniaxial extension tests
2.5. Large deformation mechanical tests
2.6. Bread quality
2.6.1. Bread making
2.6.2. Specific volume
2.6.3. Crumb firmness
2.6.4. Crumb and crust color
2.7. Statistical analyses
Data corresponding to the factorial design of experiments were statistically analyzed performing ANOVA to determine which effects were significant within the 95% of confidence interval. Data obtained from the characterization of optimum, control and regular dough were analyzed to determine if there were honest significant differences (HSD) between the three formulations, by the Tukey test within the 95% of confidence interval. All the analyses were performed using the statistics software Statgraphics Centurion XVI (Statpoint Technologies, USA).
3. Results and discussion
3.1. Baking performance
The results obtained from development and gas release curves corresponding to the 23 factorial design of experiments are given in Table 1. An experimental design analysis was performed to calculate the effects of each enzyme and their interactions and ANOVA was applied to test the statistical significances. From development curves, the enzymes had significant effect (p < 0.05) on the weakening coefficient (W) and time to dough development (t1). The weakening coefficient (W) relates the maximum height developed by dough with the height after 3 h of test, and since dough height is correlated with final loaf volume, a low W is desired.
The multiple regression analysis was performed to obtain the combined effect of TG, Gox and HE on W as shown in Fig. 1 and the fitted model is (r2 ¼ 0.892):
W¼þ5:67:32:103102TG1GoxTGþ11::90GoxTGþHE35:26:9HEþGoxHE±9
The optimized response correspondent to the minimum W over the indicated region in Fig. 1, for the quantity of TG of 4 mg/100 g, indicated that the central point of design, corresponding to the dough formulated with 4.0 mg/100 g of TG, 2.5 mg/100 g of Gox and
Fig. 1. Weakening coefficient (W) as a function of glucose-oxidase and xylanase content at a concentration of transglutaminase of 4 mg/100 g, obtained from development curve during fermentation monitoring of the dough produced according to a full factorial design 23, with the central point in triplicate.
0.5 mg/100 g of HE, is included presenting an average W lower than 5% and much lower than regular dough (W ¼ 12.2%).
With respect to t1, Gox had a positive effect (p < 0.05), increasing the time that takes to reach maximum height. This is not necessarily a desirable effect, since dough could be required to reach adequate height fast to avoid big delays during process. However, in this case, the fact that t1 is higher when Gox is added is related to the strength of the dough, which along the 3 h of fermentation continues retaining all the gas that is being produced by the yeast.
Height developed by dough during fermentation is related to loaf specific volume; therefore maximum height (Hm) and adjusted maximum height (Hmadj) are important parameters when evaluating baking performance. The estimated effects of enzymes on these parameters were not statistically significant (p > 0.05), and according to the results obtained for response surface for W, the development curves of dough formulations with W less than 12.2% are shown in Fig. 2, for comparison. It can be observed that the dough formulated corresponding to the central po
2.3. Baking performance test2.4. Uniaxial extension tests2.5. Large deformation mechanical tests2.6. Bread quality2.6.1. Bread making2.6.2. Specific volume2.6.3. Crumb firmness2.6.4. Crumb and crust color2.7. Statistical analysesData corresponding to the factorial design of experiments were statistically analyzed performing ANOVA to determine which effects were significant within the 95% of confidence interval. Data obtained from the characterization of optimum, control and regular dough were analyzed to determine if there were honest significant differences (HSD) between the three formulations, by the Tukey test within the 95% of confidence interval. All the analyses were performed using the statistics software Statgraphics Centurion XVI (Statpoint Technologies, USA).3. Results and discussion3.1. Baking performanceThe results obtained from development and gas release curves corresponding to the 23 factorial design of experiments are given in Table 1. An experimental design analysis was performed to calculate the effects of each enzyme and their interactions and ANOVA was applied to test the statistical significances. From development curves, the enzymes had significant effect (p < 0.05) on the weakening coefficient (W) and time to dough development (t1). The weakening coefficient (W) relates the maximum height developed by dough with the height after 3 h of test, and since dough height is correlated with final loaf volume, a low W is desired.The multiple regression analysis was performed to obtain the combined effect of TG, Gox and HE on W as shown in Fig. 1 and the fitted model is (r2 ¼ 0.892):W¼þ5:67:32:103102TG1GoxTGþ11::90GoxTGþHE35:26:9HEþGoxHE±9The optimized response correspondent to the minimum W over the indicated region in Fig. 1, for the quantity of TG of 4 mg/100 g, indicated that the central point of design, corresponding to the dough formulated with 4.0 mg/100 g of TG, 2.5 mg/100 g of Gox and Fig. 1. Weakening coefficient (W) as a function of glucose-oxidase and xylanase content at a concentration of transglutaminase of 4 mg/100 g, obtained from development curve during fermentation monitoring of the dough produced according to a full factorial design 23, with the central point in triplicate.0.5 mg/100 g of HE, is included presenting an average W lower than 5% and much lower than regular dough (W ¼ 12.2%).With respect to t1, Gox had a positive effect (p < 0.05), increasing the time that takes to reach maximum height. This is not necessarily a desirable effect, since dough could be required to reach adequate height fast to avoid big delays during process. However, in this case, the fact that t1 is higher when Gox is added is related to the strength of the dough, which along the 3 h of fermentation continues retaining all the gas that is being produced by the yeast.Height developed by dough during fermentation is related to loaf specific volume; therefore maximum height (Hm) and adjusted maximum height (Hmadj) are important parameters when evaluating baking performance. The estimated effects of enzymes on these parameters were not statistically significant (p > 0.05), and according to the results obtained for response surface for W, the development curves of dough formulations with W less than 12.2% are shown in Fig. 2, for comparison. It can be observed that the dough formulated corresponding to the central po
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